1. Loading of Phosphorus and Sediment to the South End of Cayuga Lake
LOADEST Estimates Based on CSI-Volunteer Synoptic Sampling Partnerships,
Tompkins County Water Resources Council
April 21, 2014

2. Cayuga Lake Watershed: CSI Monitoring Sites

3. Synoptic Sampling of Streams, From Mouth to Headwaters
Volunteer groups monitor tributary streams in southern Cayuga Lake watershed
“Monitor” means that groups perform synoptic sampling several times per year at fixed locations along a stream’s entire length
CSI’s lab performs certified analyses of synoptic samples for phosphorus, sediment and other water quality parameters
Results are posted on CSI’s website and may be searched and downloaded free of charg

4. Combine Synoptic Monitoring Results with USGS Flow Measurements
Load = Concentration x Flow
= mg/L x L/sec
Transform units to get load in tons/year
Concentrations come from synoptic monitoring
Flows come from USGS gauging stations
Flows estimated in absence of gauging station
LOADEST Calculations by Dr. Matthew Yarrow

5. Simple step-by-step description of LOADEST Load Estimation Methodology
More Info 1
Download Phosphorus concentration data from CSI Website
Website 2
Download daily average and instantaneous flow data from USGS website 3
Download Latest LOADEST version (2013) and documentation 4
Calculate watershed area at CSI monitoring location - StreamStats 5
Estimate flows at CSI monitoring site using watershed are ratio method 6
Create Calib file for each analyte (SRP and TP) including instantaneaous flow estimations and CSI concentration data
TP_Calib!A1 7
Create Est file using daily average flow data 8
Run LOADEST for Model 1 and using model auto-select option 9
Select model with best model fit stats for a given analyte and watershed
Model Fit'!A1 10
Obtain load results from LOADEST for each parameter for selected model
Load_Results!A1 11
Sum loads over water years to get final yearly load numbers
Yearly Totals'!A1 12
Optional step: determine days with significant stormwater flow in order to estimate loads occurning during stormwater events versus days with base flow.
Online baseflow separation tool
LOADEST Documentation
Runkel, R.L., Crawford, C.G., and Cohn, T.A., 2004, Load Estimator (LOADEST): A FORTRAN Program for Estimating Constituent Loads in Streams and Rivers: U.S. Geological Survey Techniques and Methods Book 4, Chapter A5, 69 p.

7. Sediment Loading To Fall-Virgil Creek
TSS Loads (tons/yr)
2009
2010
2011
2012
2013
Davis Road Bridge
558
500
1502
409
733
Virgil Creek Freeville
1736
1686
6090
1083
2598
Fall Creek Freeville
1340
1220
3816
954
1807
Freese Road Bridge
7834
8435
35432
4118
13774
Cayuga Street Bridge
10946
10882
40862
6562
16996

8. Total Phosphorus Loading to Fall-Virgil Creek
TP Loads (tons/yr)
2009
2010
2011
2012
2013
Davis Road Bridge
2.86
2.49
6.10
2.37
3.48
Virgil Creek Freeville
2.95
2.59
7.02
2.32
3.72
Fall Creek Freeville
4.03
3.52
8.89
3.30
4.96
Freese Road Bridge
12.28
10.80
29.22
9.66
15.46
Cayuga Street Bridge
15.06
13.40
38.49
11.41
19.45

9. Soluble Reactive Phosphorus Loading to Fall-Virgil Creek
SRP Loads (tons/yr)
2009
2010
2011
2012
2013
Davis Road Bridge
1.46
1.27
2.95
1.24
1.75
Virgil Creek Freeville
0.92
0.80
1.87
0.78
1.11
Fall Creek Freeville
1.78
1.55
3.62
1.51
2.14
Freese Road Bridge
3.53
3.07
6.65
3.09
4.18
Cayuga Street Bridge
3.24
2.82
6.34
2.80
3.87

10. Sediment (TSS) Loading from Major Tributaries to Cayuga Lake (tons/year)
2011
2012
2013
Average
Fall Creek Mouth
40,862
6,562
16,996
21,473
Six Mile Creek Mouth
30,241
3,202
4,343
12,595
Cayuga Inlet Mouth
43,388
8,366
8,475
20,076
CI – Farmers Market
51,933
7,642
8,191
22,589
Cascadilla Creek Mouth
2,240
633
615
1,163

11. Total Phosphorus Loading from Major Tributaries to Cayuga Lake (tons/year)
2011
2012
2013
Average
Fall Creek Mouth
38.49
11.41
19.45
23.11
Six Mile Creek Mouth
17.56
4.57
4.55
8.89
Cayuga Inlet Mouth
45.26
13.42
12.61
23.76
CI – Farmers Market
45.80
11.91
11.40
23.04
Cascadilla Creek Mouth
3.88
1.74
1.56
2.39

12. Soluble Reactive Phosphorus Loading from Major Tributaries to Cayuga Lake (tons/year)
2011
2012
2013
Average
Fall Creek Mouth
6.34
2.80
3.87
4.34
Six Mile Creek Mouth
2.12
0.99
0.89
1.33
Cayuga Inlet Mouth
5.18
2.21
2.02
3.14
CI – Farmers Market
4.84
2.10
1.92
2.95
Cascadilla Creek Mouth
1.26
0.60
0.54
0.80

13. Comparisons of Average Loads for Sediment (TSS), Total Phosphorus and Soluble Reactive Phosphorus
Average TSS Load (tons/yr.)
Average TP Load
(tons/yr.)
Average SRP Load
TP/TSS
x 1,000
SRP/ TP
Fall Creek Mouth
21,473
23.11
4.34
1.07
0.19
Six Mile Creek Mouth
12,595
8.89
1.33
0.71
0.15
Cayuga Inlet Mouth
20,076
23.76
3.14
1.18
0.13
CI – Farmers Market
22,589
23.04
2.95
1.02
Cascadilla Creek Mouth
1,163
2.39
0.80
2.06
0.33